Alternating-current welder



Dec. 16, 1941. L. F. KI GERY 2,266,323

ALTERNAT ING- CURRENT WELDER Filed Jan. 2, 1940 2 Sheets-Sheet 1 INVENTOR LJVKz'ngery BY ml-.1: viz/241E:

ATTORNEYS Dec. 16, 1941 L. F. KINGERY ALTERNATING-CURRENT WELDER Filed Jan. 2, 1940 2 Sheets-Sheet 2 1NV ENTOR. L. F. Kzngery BY 3 a ATTORNEYS.

Patented Dec. 16, 1941 ALTERNATING-CURRENT WELDER Leroy F. Kingery, Stockton, Califi, assignor of one-half to Hickinbotham Bros., Ltd, Stockton, Calif., a corporation of California Application January 2, 1940, Serial No. 312,004

5 Claims.

This invention relates in general to electric welding apparatus, and in particular the invention is directed to an improved electric welder of the A. C. type.

The principal object of the present invention is to provide an A. C. welder including mechanism designed to effect a stabilization of the welding arc; such mechanism including a secondary coil flexibly mounted in relation to the primary coil. 7

Another object of the invention is to provide simplified means for readily moving the secondary coil relative to the primary coil, and to maintain the coils in any relative or adjusted position.

A further object of the invention is to provide an A. C. welder characterized by its perfection of current control, and by its relatively great range of current values; the range being extended much farther in the lower current values than is ordinarily accomplished.

A further object of the invention is to produce a simple and inexpensive device and yet one which will be exceedingly elfective for the purpose for which it is designed.

These objects I accomplish by means of such structure and relative arrangement of parts as will fully appear by a perusal of the following specification and claims.

In the drawings similar characters of reference indicate corresponding parts in the several views:

Figure 1 is a front elevation of the improved welder.

Figure 2 is an enlarged back elevation of the welder, the housing or case being in section.

Figure 3 is a transverse section on line 33 of Fig. 2.

Figure 4 is a sectional plan on line 44 of Fig. 2

Referring now more particularly to the characters of reference on the drawings, the device includes a transformer assembly which comprises a laminated, rectangular elongated core I disposed in upstanding position; said core including a central leg 2. Wooden side rails or clamps 3 are secured on opposite sides of the bottom horizontal portion 4 of core I and extend to and are connected with the sides of a housing or case 5 which encloses the transformer and related mechanism. Outwardly facing lengths of angle iron 6 are secured on and parallel to the upper horizontal portion 1 of the core, and such angle irons also are connected at their ends on the case adjacent its upper end and immediately be- 55 low its removable lid 8. By means of rails 3 and angle irons 6, the core is rigidly secured in case 5. The case is supported on casters 9 to facilitate movement of the device from place to place.

The primary coil II) of the transformer is of usual construction and is wound about the lower end portion of the leg 2 of core I; such primary coil including leads II which extend upward to connection with spaced terminals I2 on a rectangular, dielectric terminal plate I3 surrounding leg 2 at its upper end but beneath core portion I. Grommets I4 of dielectric material are fitted in the adjacent side of the case and are adapted to receive the current supply cables (not shown) leading to terminals I2.

As is customary, the secondary coil I5 is mounted for movement relative to the primary coil Ill and core leg 2; the secondary coil I5 being of the honeycomb type and in this structure being arranged for vertical movement to and from a position encircling and overlapping the primary coil. The coil I5 includes vertical securing strips I6 adjacent the outside corners, and said strips I6 are connected with inwardly facing angle members I! disposed vertically in the inside corners of the coil by means of insulated tie bolts I8. Strips I6 and angle members ll are of dielectric material.

A shaft I9 extends transversely above angle irons 6 and is rotatably supported by spaced bearing blocks 20 mounted on said angle irons; one of said bearing blocks including an adjustable friction sleeve or drag 2| whose adjustment is accomplished through the medium of a bolt 22. At one end the shaft projects through the front of case 5 and is provided with a crank 23. Flexible metallic cables 24 are secured in winding relation on shaft I9 at points beyond but adjacent bearing blocks 26; one of said cables depending to one corner of the secondary coil, there passing through a pulley 25 on the coil and thence extending upwardly to a fixed connection adjacent the shaft. The other cable extends horizontally above plate 23 to a direction changing pulley 26 and then extends down through a pulley 21 on the opposite corner of the secondary coil and returns to a fixed connection adjacent pulley 2B. The horizontal portion of said other cable is separated from possible contact with terminals I2 by means of an over-- hanging shelf 28 mounted on the adjacent angle iron 6. With rotation of the crank 23 in one direction or the other, the secondary coil I5 is raised or lowered to any desired position relative to the primary coil I0, and when the crank is released the secondary coil remains suspended in such position as friction sleeve 2! prevents rtation of shaft l9 under the influence of the weight of such secondary coil.

Vertical movement of the secondary coil is guided by means of vertical guide posts 29 of angle shape and dielectric material; such posts being four in number and extending upward from rails 3 to dielectric plate [3. These .posts are slidablyengaged in guided relation by members I! on the secondary coil. By reason of such arrangement the secondary coil can move vertically without restriction but cannot shift-laterally.

Metallic plates or shields 38' are secured between adjacent ones of the. posts and extend upward from a point adjacent the upper end of the secondary coil; one opposed pair of these plates extending up to the horizontal; plate l3, while the other opposed pair terminate short of plate I3 in order to assure proper ventilationabout .theportionv of leg 2 within the planeofplates30.

The secondary coil 15. is provided with leads 3| which extend from said coil to a pairof plug.in" connector terminals 32' on the front of the case 5 and to which the welding or outlet cables (not shown)- are adapted to be connected. A. pointer 33 is carried by the secondary coiland projects through a vertical slot 34 in the case; said pointer registering with a scale..35 on the front of .the case adjacent slot 34. This scale reads interms of welding heator current.

In, use, the secondary coil 15 is adjusted to. a desired position relative to the primary-coil l5 and as indicated by pointer33 on scale 2l5. As the secondary coil is flexibly suspended by cables 24, such coil is free to'move upward. When both the primary and secondary coilsare energized, thereexists a magnetic repulsion therebetween which raises the secondary coil upward a slight but nevertheless certain distance. relative tov the primary coil; such repulsion being strongerwith a rise in the output current of the welder as when the distance between theelectrodeand the work is decreased. The above floating movement of the secondary c'oilidue-to such magnetic repulsion, tends to 1 stabilize the welding are by damping out violent fluctuationsin theoutput current and which are the result of the operators inability to maintain a constant distance. between. the electrode and the work.

:T'he-metal plates 3%) serve as magnetic shields or screens which extend the current range of the welder into the lower current values, 1. e. they enable the current to'be reduced to a point much.

lower than with an ordinary welder. This. re-

sult is accomplished by reason of the factthat.

the shields. 3iiincrease the leakage reactance of the-transformer when set for the lowercurrent values.

in the magnetic shields or screens 3!], and which eddyrcurrentsin turn react on the currentin the secondary-coil and tendto. assistv the ffloating secondary coil in damping. out violentfluctuations.

in the=welding:cur.rent.

.Jn. order to assure proper. ventilation. through.

thecase 5:. andabout .the enclosed apparatus, the.

Also, the current in the secondarygcoilat the. low currentvalues induces eddy currents ingan elongated core, a primary coil wound about a portion only of the core, guide members of substantial length-extending parallel to the 'coreand primary coil and spaced thereabout, a

secondary coil surrounding the core and said members andcooperating with the latter for guided movement in a direction lengthwise of said core, a-magnetic shield surrounding another portion of the core'and supported by said members clear otthe path-of movement of'the secondary coil, and means to move said secondary coil in said direction.

2..In an electric welder, a transformer including anelongated vertical core, a primary coil wound about aportion only of said core, vertical guide posts of dielectric material spacedabout the core and primary coiland extending substantially the length of said core, a secondary coil surrounding said core and posts and cooperating with theexteriorof the latter for guided movement in a direction lengthwise of said core, and a magnetic shield surrounding another. portion of the core and supported by said postsin spaced relation to the core and in clearance relation to the path of movementof the secondary coil, and means to. move said secondary coil in said direction.

3. A device as in claim 2 in. which said shield comprises metallic plates disposed in. substantially edge to edge relation and forming an enclosure about the core the posts: being inwardly facing anglemembers which symmetrically engage and are secured with. adjacent edge portions of adjacent plates.

4. A device as in claim 2 in. which the shield comprises metallic plates disposed in substantially edge to edge relation and forming an enclosure about the bore, said shield being above the primary coil and extending upward therefrom to the upper end of the'core, a dielectric plate supported. by said posts at their upper ends, terminals on said plate, and wires leading downward between .the postsand shield and connecting with the primary coil.

5. A device as in claim 2 in which theshield comprises metallic plates disposed in substantially edge' to edge. relation and forming an enclosure about the bore, said shield being above the primary coiluand extending upward therefrom to. theupper; end of the. core, a'dielectric plate supportedby said posts at their upper ends, terminals on said plate, and wires leading downwardbetween the. posts and shield and connecting with. the primary coil; said dielectric plate enclosing ithelarea between said, posts, and certain onesofthe metallic plates terminating short thereof and of the primary coil whereby toallow of .an upward circulation .of air through said shield and about said other portion of the core.

. LEROY F; 'KINGERY. 

